Esport,
they are 1.56 oz and the 255s are 1 oz (.99) so for 2 more ozs you get 5 pole motors and a much more diverse servo IMO. They are standard size MG servos. The speed is .17 @ 6Vts and 76.37 oz of torque. My concern with the 255s is the size and design of the servo. Being minis I am concerned about the surface size they will control. I am leaning toward the 454s
Jeff